[LeetCode] Majority Element

Question：

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.

You may assume that the array is non-empty and the majority element always exist in the array.

1、题型分类：

2、思路：

3、时间复杂度：O(n)

4、代码：

public class Solution {
    public int majorityElement(int[] nums) {
        Map<Integer, Integer> map=new HashMap<Integer, Integer>();
        int majorCnt=0,major=0;
        for(int i=0;i<nums.length;i++)
        {
            int t=map.get(nums[i])!=null?map.get(nums[i]).intValue()+1:1;
            if(t>majorCnt) 
            {
                majorCnt=t;
                major=nums[i];
            }
            map.put(nums[i], t);
        }
        return major;
    }
}

 

5、优化：

6、扩展：